Creating Brynne’s Kissing Giraffe

Last year I started the TailoredToys project, my non-profit work of creating custom toys for special kids. While there is a process for applying for a TailoredToy, sometimes I will just go and choose an unsuspecting family because I have been inspired by them or their child.

Admittedly, I do not know little Brynne very well. Her dad had told me a few times that she loves giraffes, and when I did get to meet her, she was sucking on a giraffe pacifier, like the one shown here. I could see she loved it–it seemed as though she was kissing it, and it struck me then that she should have a great giraffe toy.

Later, the notion came to me of a toy giraffe that would love kissing Brynne, and it would show delight by lighting up and wiggling its tail. As a designer I try not to fall in love with ideas (it will block you from better ideas), but I couldn’t put the idea down. In the middle of my main whiteboard, surrounded by all types of other work, I drew a simple giraffe so as not to forget the toy until I had time to begin.

Design

Form

We all know what a giraffe looks like. However, before carving an animal I find I need to study it to really understand its shape. I looked through hundreds of giraffe photos (especially heads), then began sketching while checking the nuances in the photos. I then simplified it with bolder lines until I felt I had a form that was simple yet familiar.

The amazing giraffe form

My son and I being “kissed” by a giraffe

Poplar wood, lined up for optimal gluing

Wood Selection

For years I have been holding on to a short board of poplar, and it was my first choice for this project. Poplar is a utility wood used to make paper, plywood, etc., and although it is probably the most affordable hardwood in America, it is an easy wood to carve, keeps a nice edge, has a light figure and glues well. I felt that the cream color of its sapwood would match the light parts of a giraffe.

Circuit Design

Schematic

Circuit in breadboard

The underlying circuit for this toy is rather simple. There is a push-button switch that toggles two 10mm LEDs (the horns) and a motor (the tail). Even though this is a low-voltage circuit, resistors are needed to protect the LEDs from burning out (note: I don’t remember how I arrived at a 27 Ohm resistor, but that is too few; 82 Ohms would have been a better choice based on this online LED calculator). Also, a “flyback” diode is needed to eliminate a spike in voltage that would occur when the circuit is quickly switched off yet the motor has not come to a complete stop (i.e. producing an inductive load).

Battery Optimization

I needed to research battery designs to understand which type of battery was optimal. I wanted a small form factor, long life and minimal wasted energy (e.g. through heated resistors). I assumed I’d use a 9V battery, but I was surprised to learn that a 9V (~565 mAh) would burn out much faster than AAA batteries (~1200 mAh each)–plus I didn’t need the extra voltage.

I would have used 2 AAA batteries (total of 3V), but my motor required 3V, so I needed 3 AAAs (4.5V) to power the motor and the LEDs.

Building

The Body

I used the depth of the wood piece to be the basis of a ratio of the widths of the key body parts:

2w Head : 1w Neck : 3w Body : 1w Leg

To maximize the wood usage, I cut the wood into three equal parts and traced only part of the body on each piece: the middle piece went from the top of the neck down to the bottom of the belly, while the other two pieces went from the feet up to above the top of the shoulder. The leftover cutouts were then used for other parts of the body (e.g. head, ears, etc.).

Cut to 3 equal lengths

Outline traced

Scrollsaw

Cutout of body

The Tail

Originally I wanted the tail to wag back and forth, and I figured I could find a way to use a vibration motor to do that. However, the vibration motor I had available in my lab was the micro-size, and after testing it I felt that not only was it too subtle, but it was too fragile to be connected to the externals of a toy.

I decided to use a low-voltage gear motor and directly attach a leather tail. I used a small piece of leather from a bag of scraps I’ve been holding onto for about 15 years. I attached the leather directly to the gear and firmly clamped on a thick split washer using my pliers.

Testing the motor with the tail attached proved that even after lighting the LEDs there was enough torque for what I needed, though you can’t tell by the photo.

Vibration motor too weak

Thick leather tail

Gear motor in circuit

Plenty of torque

The Insides

To keep things simple, I only carved out the middle piece of wood. This worked out well since it was almost exactly the depth of the motor and the battery holder.

I used the scrollsaw to cut out the main parts and then did detail work with the dremel. I drilled a hole for the tail and a hole along the length of the neck for the wires to the head. This required drilling from both sides, as I did not have a bit that was long enough. I also spent some time making sure the motor was housed snugly, and that the tail could rotate freely without obstruction.

For additional sensory input, I decided to make the whole toy a rattle. This was done simply by drilling out a cavity that would hold small metal ball bearings.

First cuts by scrollsaw

Neck drilled from both sides

Motor on top of batteries

All fitted, with wiring

The Battery Cover

Using some of the leftover wood from the original cuts, I made a small battery cover door that was held in place by screws. On it I glued small wings to hold the top battery in place. Once I was sure the battery cover was the correct size, I drilled and countersunk the holes.

Battery cover

Wings to hold battery

Once all the insides were in place, I soldered and tested the wiring, making sure to label the wires. I painted on wood glue to all the wood-to-wood connection areas, and I glued and screwed the black battery holder in. Before applying the other side of wood, I poured in the ball bearings for the rattle.

Glued & clamped overnight

The Head

Let me be the first to say that the implementation I ended up with for the giraffe’s head was almost laughably over-complicated. I felt that it was important to make sure that the head could be pulled in any direction and not damage the components or the mechanism. I jumped in with the sense that I understood the path to completion, but ended up needing to tweak things enough that I would have saved some time by considering additional design approaches.

Balancing happy, cute & realistic

The Mechanism

The main idea of the mechanism is that the head can slide backwards along a controlled path until it engages the push-button switch, making the giraffe delight. When the head is released, a spring returns the head to its original position.

The default head positioning is based on the “rest” state (i.e. not kissing), so I cut a notch out of the neck so the back of the head would be more flush with the neck.

The head moves along a shaft, as does the spring, and this (along with the embedded neck) keeps the head in its proper place. I used Instamorph to smooth out the threads of the screw so the spring would not catch in them, and I used a series of washers to keep the spring compressed. I ended up needing an additional screw to firmly hold the shaft in a locked position.

The switch was glued into a small embedded recess, but I put a small screw behind the switch to ensure it wouldn’t be pushed out of place.

Cut from leftover cutout between legs

Notched neck for flush "rest" position

First iteration of smoothed spring screw

The Horns

LEDs diffused by sanding

Dremeled cranium with LED placement

The white LEDs I had were clear and too bright when you looked directly down on them. I sanded them to give them a diffused look, which worked well. I embedded them at a slight backward angle, and I made a V pattern with the leads to anchor them in place. I glued the path and glued in a small piece of wood to lock things in place.

The Ears

Preparing ear placement

I carved the ears to fit the sides of the head (though I would do it the other way around if I were to do it again because it was really hard to get them to be flush on the contoured surface). They were held in place by screws from the inside.

The Face

I clamped the head together and carved the face, paying special attention to minimizing the appearance of the seamline. I sanded it and painted the eyes and smile with the edge of an Exacto knife.

Clamped to check ear placement

Head with ears attached

Eyes painted with Exacto knife

Carving

Carving is always my favorite part. It is where you can feel things taking form, like you are breathing life into it.

Stylistically, I decided go with a rough-carved feel (i.e. obvious cut marks with no sanding) and to give the lower part of the body a “blocky” feel, which at least for me gives a reminiscent feel of “wooden toy”. The hooves, for example, were left entirely rectangular, though I did extend the “fur” down to where the supposed hoof-line would be.

The Fur Pattern

The distinctive fur pattern of the giraffe ended up being simple to mimic. I drew with a pencil random polygonal blocks with a consistent padding space between them. I started to carve with the V-tool, but I quickly realized that that was going to take a long time and have inconsistent results. I quieted the purist in me and used the dremel instead, which was definitely the right tool.

Many giraffes I studied had a print that became smaller below the shoulder and faded out at the knee.

Rough carved

Starting to take shape

Fur pattern outlines

V-Tool was taking too long

Dremel was fast and consistent

Finishing

I chose Minwax’s Gunstock stain because it matched closely to the color of the tail, and I hand stained just the elevated parts of the fur. Some areas needed a second or third coat, and it needed to set for at least a day; otherwise, it would rub off.

I followed that with a couple coats of paste wax. Normally I like the feel and finish of paste wax, but this time it was kind of a mess. It required cleaning out the grooves with each coat (I used a small metal dentist’s pick, which worked well) and left a number of white moisture spots that needed removing. Thin coats of polyurethane might have been a better choice. Ultimately though, I was happy with the final finish.

Finishing the Battery Cover

I decided to label the battery cover’s orientation to improve the usability of changing the batteries. The battery cover fit nicely when it was screwed in. Afterwards, I painted the screws the same color as the wood to conceal them as much as possible.

Stained to match tail

Paste wax finish

Labeled battery cover

Closed battery cover

Switch soldered and coated

Soldered resistor

Inside a giraffe's head

Now for the trickiest part: the final assembly of the head. There was a lot of ways this could have gone wrong, such as things not fitting in such a tight space, wires short circuiting, or worse: gluing it all together and it doesn’t work. Here is roughly the process I used:

Soldered the correct wires to the switch leads and coated one end with liquid electrical tape

To the other end I soldered on the resistor and coated the finished joint.

Attached the left side of the head by screwing in the shaft lock screw.

Soldered the left side LED to the resistor and last wire.

I put the right side of the head mostly in place (less than an inch of opening), and through some kind of miraculous Mensa feat, I:

soldered the right LED

coated the contacts with liquid electrical tape

glued it together and clamped it

Trust me, it was much harder than it sounds. Did it work? Well, here was the final result:

Packaging

Towards the beginning of the project I went to the fabric store and bought some giraffe print (surprisingly affordable). I intending on making some nice padded box with the material and use that to send the gift, but, in the rush of life, I ended up just wrapping Brynne’s Kissing Giraffe in the fabric and some bubble wrap.

I included a letter the explained things a bit, as well as a brief instruction manual that talked about how it works and what it is made of. It had witty do’s and dont’s like:

This giraffe does not know how to swim, so do not take him in the bath with you.

I packed him up, said goodbye, and mailed him off to a happy life with Brynne.

Lessons Learned

Here are a few improvements I’ve considered:

Include a subtle heart shape in the fur pattern.

Could have dremeled the fur pattern after staining to simplify the staining process.

Focus more on connecting the packaging with the toy. For example, it could have been his home or bed.

The head design needs to be simplified while also reducing the likelihood of early wear-out.

The LEDs might have been a bit too bright. Perhaps they should be covered with a semi-transparent coating.

The ears might have been better if there were a recess in the head for them (like the LEDs) rather than them being carved to fit the contour of the head.

The paste wax could have been replaced with a polyurethane to better protect the wood.

The design is permanently sealed, and it would have been better to have a design that would allow disassembly (for fixing things), without sacrificing the look of the giraffe.

And my closing remarks here are the same for you as they were for Brynne in her letter:

“I wish for you a life filled with wonder, that you may be often amazed, and that
you will always take delight in the affection of those who love you.”

About
Tyler

Tyler Bengtson is a designer and product manager working in San Jose, California. He is ever inspired, easily amazed, eager to learn and happy to share at Redevised.